Hardcover first edition first printings of the 1997 book are the ‘Holy Grail’ for Potter collectors, according to AbeBooks.

Signed copies of the books are now worth up to four figures. Only 500 were published and 300 went to libraries, making them hard to come by.

Prices on Abebooks, which specialises in rare books, vary from $40,000 to $55,000 (£40,000) while a handful of advance proof copies are available from $7,500 to $13,500

“The first editions of the deluxe edition from 1999 are also desirable with prices from $450 to $2,500.

Paperback first editions of the Philosopher’s Stone are also quite scarce and attract four-figure price-tags – sometimes five figures if in excellent condition”, the website says.

Harry Potter and the Chamber of Secrets

Look out for: JK Rowling’s signature

“In 1998, JK Rowling was still a jobbing author rather than a worldwide superstar richer than the Queen, so there are a reasonable number of signed first editions available from her book tour signings”, the AbeBooks says.

Printing for the first hardcover of the Prisoner of Azkaban was stopped mid-printing after it was discovered that ‘Joanne Rowling’ and not ‘JK Rowling’ had been printed on the copyright page.

Those fortunate to have the ‘Joanne’ version can hope to sell their editions from £1,500 to $12,000.

It’s unknown how many copies with the error were actually created, which makes it that much more valuable.

According to AbeBooks, deluxe editions with green cloth of 1999 are also collectible if they’re first edition. Second printings can be picked up for three figures.

Harry Potter and the Goblet of Fire

Look out for: JK Rowling’s signature

By the time the fourth book was released, JK Rowling was signing far fewer copies meaning those with the author’s signature can be worth over $10,000.

AbeBooks explains: “Look out for the limited editions with original watercolour illustrations by Giles Greenfield (Bloomsbury’s UK edition) and Mary GrandPre (Scholastic’s super rare US edition of only 25 copies). If either illustrator has signed a copy, then prices are again in four-figures.

“Many buyers are also looking for books accompanied by items such as entrance wristbands or golden tickets from events where JK Rowling has conducted a signing. After the Goblet of Fire, these signing events have become increasingly scarce.”

Harry Potter and the Order of the Phoenix

Look out for: JK Rowling’s signature

Those lucky enough to have been at JK Rowling’s midnight launch event in Edinburgh in 2003 will be glad they made the journey as signed copies of the Order of the Phoenix are worth four figures. Illustrator Jason Cockroft also signed books which are now worth around $200.

Harry Potter and the Half-Blood Prince

Look out for: Signed copies

The Half-Blood Prince was published at the height of Pottermania where JK’s book tours were less common. Signed copies of the book are very few in number but those which are available go for up to $5,000.

Copies signed by illustrator Mary GrandPre are worth around $250.

Fantastic Beasts and Where To Find Them & Quidditch Through the Ages

Fantastic Beasts and Where To Find Them & Quidditch Through the Ages were published in 2001 in aid of Comic Relief by Arthur A Levine Books.

“Rowling’s contributions are copies of titles in the Hogwarts library” AbeBooks says. “Their fictional authors are Newt Scamander and Kennilworthy Whisp. Signed copies are very hard to find and immediately give these books collectible status. There are several listings for signed boxed sets of the books on AbeBooks.com that have prices between $1000 and $4,500.”

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